Anne E. Magurran
- Published in print:
- 2005
- Published Online:
- September 2007
- ISBN:
- 9780198527855
- eISBN:
- 9780191713576
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198527855.003.0007
- Subject:
- Biology, Evolutionary Biology / Genetics
The guppy raises three different classes of conservation issues. First, the species is a useful model for freshwater fish species — one of the most endangered vertebrate groups. Second, although ...
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The guppy raises three different classes of conservation issues. First, the species is a useful model for freshwater fish species — one of the most endangered vertebrate groups. Second, although guppy populations are generally large and the species is widely distributed across Trinidad, some of the diversity that has provided such rich material for evolutionary biology is under threat from pollution, habitat loss, exotic introductions, and so on. Guppy populations are also potentially at risk from scientists who observe, collect, and manipulate guppy populations. Artificial introductions have proved very informative but may lead to irreversible changes in a river. Finally, introductions of guppies to countries outside their range, either for the control of malaria vectors, or through escapes of ornamental fish, can adversely affect vulnerable faunas. This chapter discusses these issues.Less
The guppy raises three different classes of conservation issues. First, the species is a useful model for freshwater fish species — one of the most endangered vertebrate groups. Second, although guppy populations are generally large and the species is widely distributed across Trinidad, some of the diversity that has provided such rich material for evolutionary biology is under threat from pollution, habitat loss, exotic introductions, and so on. Guppy populations are also potentially at risk from scientists who observe, collect, and manipulate guppy populations. Artificial introductions have proved very informative but may lead to irreversible changes in a river. Finally, introductions of guppies to countries outside their range, either for the control of malaria vectors, or through escapes of ornamental fish, can adversely affect vulnerable faunas. This chapter discusses these issues.
Robert R. Dunn
- Published in print:
- 2009
- Published Online:
- September 2009
- ISBN:
- 9780199535095
- eISBN:
- 9780191715754
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199535095.003.0008
- Subject:
- Biology, Evolutionary Biology / Genetics
Nearly all conservation and extinction research focuses on vertebrates and plants, but most organisms on earth are poorly studied or undescribed invertebrates, the majority of which are parasites or ...
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Nearly all conservation and extinction research focuses on vertebrates and plants, but most organisms on earth are poorly studied or undescribed invertebrates, the majority of which are parasites or commensals. However, very little remains known about invertebrate coextinctions following the extinction of host species. The limited empirical evidence for recent host-affiliate coextinctions and extinction chains is critically reviewed, but provides little insight into the frequency or broader significance of this process. Models which attempt to estimate the frequency with which coextinctions occur at a global scale suggest that these events should be at least as common as host extinctions, with similar rates predicted for total numbers of prehistoric coextinctions across the Holocene. We can reconcile these two observations if the vast majority of coextinctions are unobserved, or alternately if parasites and mutualists are actually much less host-specific or are much more able to switch hosts than is currently assumed.Less
Nearly all conservation and extinction research focuses on vertebrates and plants, but most organisms on earth are poorly studied or undescribed invertebrates, the majority of which are parasites or commensals. However, very little remains known about invertebrate coextinctions following the extinction of host species. The limited empirical evidence for recent host-affiliate coextinctions and extinction chains is critically reviewed, but provides little insight into the frequency or broader significance of this process. Models which attempt to estimate the frequency with which coextinctions occur at a global scale suggest that these events should be at least as common as host extinctions, with similar rates predicted for total numbers of prehistoric coextinctions across the Holocene. We can reconcile these two observations if the vast majority of coextinctions are unobserved, or alternately if parasites and mutualists are actually much less host-specific or are much more able to switch hosts than is currently assumed.
Olivier Honnay and Hans Jacquemyn
- Published in print:
- 2012
- Published Online:
- December 2013
- ISBN:
- 9780199608898
- eISBN:
- 9780191774560
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780199608898.003.0034
- Subject:
- Biology, Ecology, Evolutionary Biology / Genetics
This chapter focuses on habitat fragmentation and how it affects plant population viability and genetic diversity in remnant habitat patches. The genetic response to habitat fragmentation is strongly ...
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This chapter focuses on habitat fragmentation and how it affects plant population viability and genetic diversity in remnant habitat patches. The genetic response to habitat fragmentation is strongly mediated by plant traits such as the breeding system. Habitat fragmentation has also been shown to negatively affect insect pollinator abundance and pollinator diversity in small habitat fragments. Fragments can become too small to sustain pollinator communities or too isolated to attract a large diversity of pollinators, both of which reduce pollinator abundance and efficiency, and therefore reproductive success of plant species. Habitat fragmentation also implies a relative increase in habitat that is prone to edge effects. Edge effects result from the matter, species, and energy flowing from patches with high-intensity land use into low-intensity land use patches. Edge effects have been shown to affect plant regeneration, interspecies competition, and plant-animal interactions such as predation, seed dispersal, and pollination.Less
This chapter focuses on habitat fragmentation and how it affects plant population viability and genetic diversity in remnant habitat patches. The genetic response to habitat fragmentation is strongly mediated by plant traits such as the breeding system. Habitat fragmentation has also been shown to negatively affect insect pollinator abundance and pollinator diversity in small habitat fragments. Fragments can become too small to sustain pollinator communities or too isolated to attract a large diversity of pollinators, both of which reduce pollinator abundance and efficiency, and therefore reproductive success of plant species. Habitat fragmentation also implies a relative increase in habitat that is prone to edge effects. Edge effects result from the matter, species, and energy flowing from patches with high-intensity land use into low-intensity land use patches. Edge effects have been shown to affect plant regeneration, interspecies competition, and plant-animal interactions such as predation, seed dispersal, and pollination.
Richard Mcelreath and Robert Boyd
- Published in print:
- 2007
- Published Online:
- February 2013
- ISBN:
- 9780226558264
- eISBN:
- 9780226558288
- Item type:
- chapter
- Publisher:
- University of Chicago Press
- DOI:
- 10.7208/chicago/9780226558288.003.0001
- Subject:
- Biology, Evolutionary Biology / Genetics
Mathematical models and the tools used to analyze them constitute the theoretician's laboratory. Simple mathematical models are experiments aimed at understanding the causal relationships that drive ...
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Mathematical models and the tools used to analyze them constitute the theoretician's laboratory. Simple mathematical models are experiments aimed at understanding the causal relationships that drive important natural phenomena. Theoreticians in evolutionary biology use a variety of tools to study such models, divining their secrets to reveal how interactions that take place over long time spans shape the evolution of behavior. These models are almost always too simple to make accurate predictions or even accurately represent how any real behavior evolves. This chapter focuses on the theoretician's laboratory and the utility of mathematical models used to study social evolution. It also discusses some of the reasons why computer simulations are poor substitutes for analytic models. It then describes a simple model of evolutionary changes that result from variation in probability of survival—a form of natural selection that populations geneticists call viability selection. Finally, the chapter introduces a very useful tool called a mating table and shows that social learning dynamics can be very similar to viability selection dynamics for simple genetic models.Less
Mathematical models and the tools used to analyze them constitute the theoretician's laboratory. Simple mathematical models are experiments aimed at understanding the causal relationships that drive important natural phenomena. Theoreticians in evolutionary biology use a variety of tools to study such models, divining their secrets to reveal how interactions that take place over long time spans shape the evolution of behavior. These models are almost always too simple to make accurate predictions or even accurately represent how any real behavior evolves. This chapter focuses on the theoretician's laboratory and the utility of mathematical models used to study social evolution. It also discusses some of the reasons why computer simulations are poor substitutes for analytic models. It then describes a simple model of evolutionary changes that result from variation in probability of survival—a form of natural selection that populations geneticists call viability selection. Finally, the chapter introduces a very useful tool called a mating table and shows that social learning dynamics can be very similar to viability selection dynamics for simple genetic models.
Glenn-Peter Sætre and Mark Ravinet
- Published in print:
- 2019
- Published Online:
- July 2019
- ISBN:
- 9780198830917
- eISBN:
- 9780191868993
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198830917.003.0004
- Subject:
- Biology, Evolutionary Biology / Genetics, Biomathematics / Statistics and Data Analysis / Complexity Studies
Natural selection is the scientific explanation for the evolution of adaptations. Wonders of the living world, such as the anatomy and physiology that grants the cheetah its unchallenged running ...
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Natural selection is the scientific explanation for the evolution of adaptations. Wonders of the living world, such as the anatomy and physiology that grants the cheetah its unchallenged running speed; the seductive colors and scents of a flower that are irresistible to its pollinators; and the accuracy and sophistication of sense organs such as the human eye are the ultimate results of this one creative force in evolution. This chapter investigates simple models of natural selection to explore its power in causing evolutionary change. Mathematical techniques including invasion fitness analysis and adaptive landscapes are powerful tools for analyzing such models and for identifying evolutionarily stable and unstable equilibria. The chapter further investigates frequency-dependent selection and evolutionary game theory. An important goal here is to show that selection can take many different forms and yield very different evolutionary outcomes.Less
Natural selection is the scientific explanation for the evolution of adaptations. Wonders of the living world, such as the anatomy and physiology that grants the cheetah its unchallenged running speed; the seductive colors and scents of a flower that are irresistible to its pollinators; and the accuracy and sophistication of sense organs such as the human eye are the ultimate results of this one creative force in evolution. This chapter investigates simple models of natural selection to explore its power in causing evolutionary change. Mathematical techniques including invasion fitness analysis and adaptive landscapes are powerful tools for analyzing such models and for identifying evolutionarily stable and unstable equilibria. The chapter further investigates frequency-dependent selection and evolutionary game theory. An important goal here is to show that selection can take many different forms and yield very different evolutionary outcomes.
